Authorities said he’s a reputed high-ranking leader of the P Stones and a nephew of the gang’s imprisoned co-founder Jeff Fort, who also founded the gang’s El Rukn faction.

Police said the $15,000-a-day operation dealt mostly heroin and cocaine in an area dubbed “Terror Town” that is loosely bounded by East 75th and 79th Streets, Yates Boulevard and Colfax Avenue.

“This is probably the most active (drug-dealing area) on the South Side and the most organized,” Sgt. Tom Cronin of the Chicago police gang investigations unit, which led the eight-month probe, said at the news conference at police headquarters.

The investigation also resulted in the arrests of 16 additional people who tried to buy drugs from undercover officers, authorities said. Four other suspects in the probe remained at large.

Police also seized roughly $25,000 in cash during the investigation as well as 900 grams of heroin, 125 grams of cocaine, 13 vehicles and 10 guns, authorities said. Inside Gauthreaux’s home, they said, police found clothing, hats and various types of handwritten artwork related to the Fort family or the P Stones.

The investigation began last September after a rash of violent crimes in the area, authorities said. The investigation was stepped up two months later after Chicago police Officer Michael Flisk, an evidence technician, was fatally shot in the area while on duty, authorities said.

Gauthreaux lives down the alley from where that slaying took place, but Flisk’s death wasn’t connected to the drug operation.

On May 19, however, Chicago Police Officer Paul Nauden was taken to a hospital complaining of chest pains while working on the investigation. The 46-year-old narcotics unit officer and 21-year department veteran died the following day at the University of Chicago Medical Center.

In addition to officers from the narcotics unit, those from the gang enforcement unit and Calumet Area assisted in the probe.

“There’s a reason that this area is called ‘Terror Town,’” said Brian Sexton, chief of the Cook County state’s attorney’s office’s narcotics prosecutions section. He offered a stern message for gang members who are still active in that area: “We’re not done yet.”